Body Systems: Circulatory System Flashcards
main function of circulatory system
transport of oxygen, nutrients, waste products and hormones among the tissues and organs of the body
circulatory system
heart, blood vessels, blood
heart
4 chambers:
- right atrium
- left atrium
- right ventricle
- left ventricle
atria
collect blood from the body and lungs and pass it to the ventricles
ventricles
eject blood throughout the body
myocardium
chamber walls consisting of cardiac muscle
- internal lining consists of a smooth membrane called endocardium
pericardium
double-layered membrane that encloses the heart
atrioventricular (AV) valves
permit one-way blood flow form the atria to the ventricles
tricuspid valve
three flaps (cusps) that meet when valve is closed between the right atrium and right ventricle
pumping cycle
chamber relax as they fill and the contract when the pump blood
- diastole: filling period
- systole: contracting period
- alternation contraction and filling called cardia cycle
sinoatrial node (SA node)
pacemaker of the heart
- initiates impulse for contraction thats spreads over atria and passes to the ventricles via conductive tissue called the atrioventricular node (AV node)
- impulse continues along and terminate in the Purkinje fibres
heart muscle contraction influenced by
autonomic nervous system and hormones such as epinephrine
sets of nerves
two sets work with one slowing the heart and the other accelerating it
- vagus nerve: slows heart rate during rest ad sleep by acetylcholine
aorta
branches carry blood to head, chest, abdomen, pelvis, and lower extremities
- arteries divide into smaller arteries and eventually into arterioles, which then lead into capillaries
- walls of arteries are muscular, thick, strong, elastic, and lined with endothelium
red blood cells (erythrocytes)
- make up half of the blood’s volume
- most abundant cells in the human body
- mature red blood cells have no nucleus
- carrying protein called hemoglobin
- short lifespan due to lack of nucleus
hemoglobin
- made up of protein called gloving and iron-containing heme molecule
- most important component of RBC
- in lungs, hemoglobin binds to o2 becoming oxyhemoglobin
plasma
- consists of mostly water carrying nutrients, wastes, ions, hormones, clotting factors, albumins, and antibodies
- clotting factors readily available, and antibodies to address any infection in body
- albumin promotes blood’s ability to hold water and maintain pressure inside blood vessels
white blood cells (leukocytes)
- produced in the bone marrow from their respective system
- primary function is to defend tissues against infections and foreign substances
- abnormalities an defects in the WBCs can result in disease and disability
platelets
- produced in bone marrow and essential for blood clotting
- clotting factors formed in the liver, enter the blood and become active in response to an injury
- during clotting formation, platelets become sticky and release a protein called fibrin which forms a dense mash at the wound, preventing blood loss
blood tests
diagnostic for systemic diseases and specific blood disorders
- measure total blood count (RBC + WBC + platelets) and other components within blood
- provides qualitative information including size, shape, and ratio
bone marrow smear
used to diagnose malignant blood disorders and increases or decreases in blood counts
- provide information on the function of the bone marrow an the qualitative characteristics of stem cells that create blood cells
electrocardiogram
electrical recording of heart action aiding in the diagnosis of coronary artery disease, myocardial infarction, valve disorders, and some congenital heart disease
echocardiography
high-frequency sound waves utilized to examine size, shape, and motion of hear structured
doppler echocardiography
explores blood flow patterns and changes in velocity of blood flow within the heart and great vessels
cardia catheterization
catheter passed into heart through blood vessels to Samp.e the blood in each chamber for O2 content and pressure
coronary arteriography
injecting a contract material to visualize blood vessel function
arrhythmias/dysrhythmias
irregular cardiac
- tachycradia: too fast
- bradycardia: too slow
cardiovascular disease
- almost 1/3 of deaths in western countries attributed to heart disease –> most by coronary artery disease and hypertension
- important ss: chest pain, dyspnea, tachypnea, palpitations. cyanosis, edema, fatigue, syncope
hyperlipidemia
- elevated lipids blood like cholesterol, phospholipids, and triglycerides
- cholesterol is transported throughout by transport protein called lipoproteins
hyperlipidemia low-density lipoprotein
- LDL
- major cholesterol carrier in blood
- accumulation of LDL can form a plaque (thick, heard deposit( that narrows arteries impeding blood flow
as blood LDL increases the risk for heart disease increases - estimated 35% of adults over 20 have high levels of LD
hyperlipidemia high density lipoprotein
- HDL
- carries 1/4 to 1/3 of the cholesterol
- generally, the higher the level of HDL, the lower the risk of coronary heart disease (CAD)
coronary artery disease (CAD)
involves arteries supplying myocardium
CAD ss
- asymptomatic inutialy
- first symptom is pain of angina pectoris
- advanced: burning, squeezing, crushing, radiating to arm/neck/jaw pain
- nausea, vomiting, weakness
CAD prognosis
- depends on response to treatment
- stop smoking
CAD diagnosis
- changes in ECG but not always recognized, can show ischaemia and arrhythmias as well
- treadmill testing
- thallium or cardiolite scan
- CT scan
- stress echocardiogram
- angiogram
- cardiac catherization
CAD treatment
- restore good blood blow to myocardium - use vasodilators
- angioplasty with a balloon or stent attempted to open constricted arteries
- reduction of plaque buildup with hypolipidemic drugs
- angiotensin converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, diuretics
- anticoagulants to prevent blood clots breaking off
- coronary artery bypass surgery if no response to drugs and angioplasty
- experimental gene therapy injecting DNA into cardia muscle to stimulate growth of new cells
CAD etiology
- deposits o fat containing plaque in the lumen of coronary arteries results in arteriosclerosis and subsequent narrowing of the lumen of the arteries causing temporary cardia ischaemia and eventually MI
- pain due to diminished blood flow and low O2 saturation
- screening important because it can be asymptomatic until a sudden death or Mi
- myocardium needs adequate blood flow to function, without enough it dies
- arteriosclerosis: hardening of the arteries so that they lose elasticity and become hard and narrow leading to cardia ischaemia
- pain not usually experienced until 75% of coronary artery is blocked
- high risk: genetic predisposition, men older than 40, post-menopausal women, caucasians, smoking, urban society residents, hypertension, diabetes, obesity, elevated cholesterol, lack of exercise, stress
CAD prevention
- diet low in fat, salt, cholesterol
- exercise
- reduce stress and smoke
angina pectoris
reduced oxygen supplied to myocardium leading to chest pain
angina pectoris ss
- sudden onset of left sided chest pain during or after exertion
- pain my radiate to left arm/back
- dyspnea, hypertension, arrhythmias
angina pectoris etiology
- atherosclerosis causes narrowing of coronary arteries, compromising blood flow to myocardium
- exercise requires increased blood flow, but vessels cannot supply it
- causes: spasms of coronary arteries, severe tachycardia, anemia, respiratory disease
angina pectoris prognosis
- depends on extent of arterial involvement
- lower strenuous activities and vasodilators can cause angina pectoris to diminish or disappear
- modify lifestyle
angina pectoris diagnosis
- ECG showing ischaemia
- similar diagnostic measures as for CAD
angina pectoris treatment
- cease strenuous activity
- nitroglycerin tablets or spray
angina pectoris prevention
- lifestyle modification
- site low in fat, cholesterol, and salt
- control of hypertension
- weight loos
- smoking cessation
- reduce stress
myocardial infarction (MI)
death of myocardial tissue caused by development of ischemia
MI ss
- left sided chest pain that is crushing, feeling like constriction of chest, burning or discomfort
- pain radiates to arms/back/jaw, not relieved by rest or nitrogylcerin
- irregular heartbeat, dyspnea, diaphoresis
- denial, severe anxiety, impending doom
MI prognosis
- 65% of deaths occur in first hour
- immediately defibrillation for ventricular fibrillation
- late mortality depend son extent of damage to muscle –> most common cause is fatal arrhythmia
MI etiology
- occlusion of coronary artery resulting in ischemia and infarct of myocardium
- results form insufficient o2 supply
- pain caused by ischemia and if ischemia is not resolved in 6 hours, cardiac muscle dies
- coronary thrombosis is most common cause
MI diagnosis
- thorough history and physicla
- ECG change in PR and QRS complexes correspond to ischemic area
- chest radiography
- lab tests for cardia enzymes
MI treatment
- O2 administration
- morphine for pain
- aspirin to reduce additional damage by ischemia
- basil dilation
- thrombolytic drugs
- angioplasty
MI prevention
lifestyle modification
cardia arrest
sudden, unexpected cessation of cardia activity
cardia arrest ss
- unresponsive
- no respiratory effort or pulse
cardia arrest etiology
- caused by anoxia (absence of o2) or interruption of electrical stimuli to heart
- can be due to respiratory arrest, arrhythmia, MI, electrocution, drowning, severe trauma, hemorrhage, drug overdose
cardiac arrest prognosis
- varies depending on time patient has been in cardia arrest
- earlier CPR into fibrillation have greater possibility for survival
- at 4:00 to 6:00 min after cessation of cardia activity, brain cells start to die
- 10 min, brain will die and death is inevitable
cardiac arrest diagnosis
- absence of respiratory effort
- lack of palpable pulse
- ECG showing verticular fibrillation or asystole
cardiac arrest treatment
- CPR initiated within 4-6 min
- AED
- antiarrhythmic drugs
- epinephrine
cardia arrest prevention
- lifestyle modifications to reduce risk
- cannot predict many accidents
- implantation of defibrillators
hypertensive heart disease
- results of chronically elevated pressure throughout vascular system
- most prevalent cardiovascular disorder in the US
- arteriosclerosis, arteriosclerosis, renal disease, anything increasing vascular pressure can cause heart tow work harder as it pumps against increased resistance
essential hypertension (primary)
abnormally high blood pressure
essential hypertension ss
- insidious onset
- few symptoms until permanent damage (headaches, epistaxis, lightheadedness, syncope)
essential hypertension etiology
- more common with old age
- is accompanied with hyperlipidemia, can lead to atherosclerosis
- ideology unknown but many factors contribute –> stress, age, heredity, smoking, obesity, sedentary lifestyle, poor diet, hyperactive
essential hypertension prognosis
- varies and depends on patients response to drug and lifestyle modifications
essentrial hypertension diagnosis
- blood pressure elevation
- systolic > 140 mmhg
- diastolic > 90 mmhg
essential hypertension treatment
- diuretics to reduce blood volume
- ACE inhibitors to produce vasodilation and increase renal blood flow
- basil dilators to dilate vessels
- CCBs to slow hr, dilate vessels
- reduce conduction irritability
- designed to fit each patient
- lifestyle modifications
essential hypertension prevention
- ideology is unknown so cannot be prevented
- alter contributing factors
malignant hypertension
life threatening, sever form of hypertension
malignant hypertension ss
- severe headache
- blurred vision
- dyspena
- sudden onset
malignant hypertension etiology
- unknown but stress is contributing factor
- at risk for cerebral vascular accident (CVA), stroke, irreversible renal damage
malignant hypertension prognosis
depends on person’s response to drugs
malignant hypertension diagnosis
blood pressure elevation
- systolic > 200 mmhg
- diastolic > 120 mmhg
malignant hypertension treatment
- aggressive intervention –> intravenous vasodilators
- monitor blood pressure
- drug therapy may need stop be continued for life
malignant hypertension prevention
- difficult because etiology unknown
- comply with drug therapy and reduce stress
- similar to essential hypertension
congestive heart failure (CHF)
acute or chronic inability of heart to pump enough blood
CHF ss
- insidious onset with patient experiencing gradually increasing dyspnea
- increased heart and respiratory rates, anxiety
- distended neck viens
- edema in ankles
- liver and spleen enlarge and peripheral edema is more prominent with right sided failure
- pulmonary congestion and more pronounced respiratory difficulties with left sided failure
CHF etiology
- underlying condition can compromise pumping action
- common cause is MI
- can be caused by hypertension, cCAD, COPD< cardia valve damage, arrhythmias, cardiomyopathy
CHF prognosis
- varies
- acute: responds well to medical interventions
- chronic: vulnerable to major organ impairment and complications
CHF diagnosis
- through history and physical
- breath sounds diminished
- radiography indicates fluid in lungs
- ECG to discover underlying causes
- echocardiogram to evaluate chamber size, ventricular function, disease of myocardium, valves, cardia structures, pericardium
- cauterization to monitor pressures in circulation